Michael Mott, 34, of Oxford was charged with assault in the incident on June 28 outside the Study Hotel in New Haven. The “Let the Great World Spin” author was treated for significant facial injuries at Yale-New Haven Hospital.

Mott confessed to assaulting McCann and turned himself in Monday evening, police said. They declined to elaborate.

A man who answered a phone listed with Mott’s address declined to comment.

Witnesses suggested McCann had tried to help a woman who was involved in a dispute in the hotel lobby, police said.

Police said Mott had a dispute with his wife after hotel staff told the couple the credit card Mott used didn’t have sufficient funds to pay for the room. McCann, 49, apparently witnessed the dispute and asked Mott’s wife if she was all right or needed help and she indicated she would be OK, police said.

McCann went outside, where he was attacked, police said. Police say Mott punched McCann, who lost consciousness.

Mott was also charged with family violence breach of peace for the altercation in the lobby, police said.

“This was a particularly disturbing case because Mr. McCann was specifically targeted after he tried helping another victim,” said Chief Dean Esserman.

McCann lives in New York City. He just released the story “Gone” through the online publisher and subscription service Byliner. It’s his first short story in a decade.